The present invention relates to a surgical covering of the kind used to make, for example, mayo stand covers, back table covers and surgical drapes.
For years, surgical covers, including mayo stand covers, back table covers and surgical drapes have been made of a laminated sheet including a nonwoven fabric adhered to a plastic film. For example, surgical drapes such as those sold by 3M (its Steri-Drape 9000) consist of a laminate of polypropylene fibers and a polyethylene film. Similar drapes or coverings are sold by Amcor Ltd and by Pliant Corp. Nonwoven materials have been the preferred surface for surgical covers and drapes because of its frictional properties (i.e., instruments do not readily slip on nonwoven surfaces) and they have the benefit of being tough, non-glaring and hydrophilic.
Such laminates are relatively expensive to manufacture because of the additional cost of the nonwoven layer, and because there is an assembly step required by which the nonwoven must be connected to a film carrier layer. In addition, in some cases, fibers from the nonwoven layer (i.e., lint) may find their way into open wounds and may thereby adversely impact the sterility of the operating room environment. Finally, composites having a nonwoven upper layer are not easily ripped or opened up, and thus restrict a surgeon's ability to access areas of a patient's body in certain situations.
At least one manufacturer (see U.S. Pat. No. 6,748,952) has attempted to make a surgical cover from a film by embossing the film after it has been extruded. While this approach does have the benefit of eliminating the nonwoven layer, this solution is also expensive to manufacture because of the separate embossing step.
In some surgical drape applications, it is beneficial to allow the drape to be ripped from the edge or opened up to allow a surgeon to access an area of a patient previously covered. Nonwoven materials are generally quite tough and are not easily ripped or opened.
Thus, there is a need for a surgical cover made from cast or blown film that results in a sheet having a textured, hydrophilic exposed surface that is non-glaring and that has the beneficial features of a nonwoven surface with respect to its frictional properties, but without the adverse aspects of a non-woven layer, such as its additional cost, resistance to tearing, and its lint-forming characteristics. The surgical cover described below has these features and advantages.
It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the inventions described and claimed herein or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the inventions described herein are not necessarily limited to the particular embodiments illustrated herein.